Why is the Human Genome Project called a mega project?

Explanation

The international human genome project was launched in the year 1990. It was a mega project and took 13 years to complete. The human genome is about 25 times larger than the genome of any organism sequenced to date and is the first vertebrate genome to be completed. Human genome is said to have approximately `3 xx 10^(9)` bp. HGP was closely associated with the rapid development of a new area in biology called bioinformatics.